Filter apparatus and filter cartridges therefor



2, 883,056 FILTER APPARATUS AND FILTER CARTRIDGES THEREFOR Filed Feb.1'7; 1956 J. MULLER April 21, 1959 4 Sheets-Sheet 1 an. gr

ATTORNEYS April 21, 1959 J. MULLER 2,833,056

FILTER AEPARATUS AND FILTER CARTRIDGES THEREFOR Filed Feb. 17, 1956beets-Sheet 2 i i I I g; I l I I E V I l c I I {Q i I L 0 I x I I I \l xw i i X3 1 Q! 1 3 N. i l i I 1 \S\' I l I gs- I N] I 1 i f m N[Annex/1'01";

M56905)" Mans/z J. MULLEr.

April 21, 1959 v FILTER APPARATUS AND FILTER CARTRIDGES THEREFOR FiledFeb. 17, 1956 4 Sheets-Sheet 3 INVENTOR flame-.5- M01151? BY ATTORNEYSApril 21, 1959 J.- MULLER 2,883,056

FILTER APPARATUSAND FILTER CARTRIDGES THEREFOR Filed Feb. 17; 1956 4Sheets- Sheet4 caaacadaksca cacacaca cacacacaeaca @@@@@ca M I I H mm m IN VEN TOR @d l/ESMULLER BY m/ v (743 ATTORNEYS States PatentO FILTERAPPARATUS AND FILTER CARTRIDGES THEREFOR [The present invention relatesto improvements in cartridges used in filtering various fluids andfiltering apparatus using such cartridges.

An object is to provide filter cartridges comprising a tubular body orcore carrying on its circumferential surface filter material and made ofembossed sheet metal such as described in my copending patentapplication No. 448,980, filed August 10, 1954, now Patent No.2,813,632.

vThis sheet metal is formed by stamping numerous small cones projectingfrom one face only and perforated at their apices.

Another object is to provide a filter apparatus embodying a cartridgecarrying partition.

For greater clearness there will now be described several modes ofcarrying out the invention with reference to the accompanying drawingsin which:

Fig. 1 is an axial cross section of a simple cartridge.

Fig. 2 is a sectional view on a larger scale of a part of the simplecartridge.

: Fig. 3 is a view in axial section of a cartridge formed of .twoconcentric bodies.

Fig. 4 is a view in axial section of a cartridge formed of two axiallyaligned bodies.

, Fig. Sis a view in axial section of a filter equipped with simplecartridges of the type shown in Fig. 1.

Fig. 6 is a perspective view as seen in the direction of the. arrow A inFig. 5, showing one side of the cup supporting the cartridges.

Fig. 7 is a perspective view as seen in the direction of the arrow B ofFig. and shows the other side of the cup.

Fig. 8 is a sectional view on a larger scale of the detail of themounting of the cup supporting the cartridge in'the housing of thefilter.

"Fig. 9 is a perspective sectional view of the sealing joint of thecartridge supporting cup.

' Fig. 10 is an axial sectional view of a simple filter cartridge inwhich the filter material is formed of stacked discs with microgrooveson their two faces according to the principle described in my US. patentapplication No. 503,933 filed April 26, 1955.

Fig. 11 is a perspective view of the tubular body of embossed sheetmetal of the filter cartridge of Fig. 10. Fig. 12 is a diagrammatic viewin perspective of two consecutive discs showing on one face only ofthem, the microgrooves on a much larger scale.

' Fig. 13 is a perspective view on a larger scale showing two fragmentsof the superposed discs.

As shown in Fig. 1, a simple cartridge according to the inventioncomprises a core or supporting element formed of a tubular body 1 ofannular cross-section on the external surface of which is stretched asleeve 2 of filter cloth or screen attached at its two ends by meanswhichwill be described in detail hereinafter.

.The tubular body is made of embossed sheet metal of the, kind in whichare fashioned by stamping numerous small cones 3 (Fig. 2), thebases ofwhich are very close to each other and which are'perforated at theirapices,

Patented Apr. 21, 1959 all said cones projecting from one surface of thesheet. According to the invention this sheet metal is rolled or foldedin a manner that all the cones extend towards the interior in order thatthe exterior peripheral surface of the tubular body will be perfectlysmooth and displays only large orifices 3a very close together. Fig. 11shows in perspective a tubular body of this type, but square in section.There can be seen the close disposition of the embossed cones 3 in thefour faces of the body, the external surface having the appearance of agrid with large meshes.

The filter sleeve 2 is stretched over this grid of which the supportingledges are of a reduced to the minimum width. The attachment of thefilter sleeve 2 is effected at the ends of the body in the manner shownon a larger scale in Fig. 2. There is used for this purpose a filtersleeve longer than the body so that it is possible to turn back its ends2a towards the interior and against the inner surface of the body. Forthe fixation there is used an annular collar or gasket 4 of U-shapecrosssection to cap eachend of the tubular body and wedge or clip thefolded ends of the filter sleeve as clearly shown in Fig. 2. The annularcollar or gasket 4 is made of a material capable of acting as a memberfor sealing fluid. The body and sleeve form an assembly which isremovable and replaceable as a unit.

The unit is mounted on one face of a cartridge carrying partition 5adapted to divide a filter chamber into an inlet compartment for fluidto be filtered and an outlet compartment for filtered fluid. In thispartition is formed a plurality of orifices 6 in the center of which isfixed a rod 7 threaded at its free end. On the side of the partitioncarrying the rod there is an annular groove 8 surrounding the circularseries of orifices the diameter of which groove is equal to that of thetubular body 1 so that it can receive one end of said body. On the freeend of the rod is freely engaged a solid cap 9- the edge of which isprofiled to form a sort of recess or gutter 10 of annular shape and ofdiameter equal to that of the body 1 so that said cap can cover theupper or outer end of said body. A clamping nut 11 engages. the threadsof the rod 7 and is provided with an expansion compensating device 12.

From the foregoing it is obvious that the mounting of a filter cartridgeis very simple. Of course finished cartridges are made available, thatis each is provided on its outer circumference with a filter sleeve 2fixed at its ends as described above. After the nut 11 and the cap 9 areremoved, a cartridge is placed about the rod 7 with its end engaged inthe circular groove 8 in the partition. The cap 9 is then placed on therod 7 and pushed against the outer end of the cartridge so that therecess or gutter 10 caps the edge of said end. Finally the nut 11 isscrewed on the rod 7 and tightened so that the tubular body is properlysecured. The tighten-, ing seals both ends of the cartridge by virtue ofthe annular collars or gaskets 4 which prevents leakage of liquid whichhas not been filtered.

Disassembling is simply effected by performing these steps in thereverse order.

Since the filter sleeve 2 is stretched over the outer circumference ofthe body 1 the filtering action must take place from the outside to theinside of the cartridge as indicated by the arrows in Fig. 1.Consequently the cartridge must be mounted in the inlet chamber of thefluid filter.

Fig. 3 shows how it is possible to filter a fluid twice using acartridge with two concentric tubular bodies 1a and 1b each similar tothe one shown in Fig. 1 and pro cartridges are similar except that thetwo bodies are mounted on a common central rod 7. It is possible tomount inthis manner a number of concentric cartridges greater than two.The advantage of this arrangement resides in .the fact that it ispossible to use filter materials with narrower meshes in the directionof filtering so that the filter sleeves retainsuccessively'first thecoarse impurities and then the foreign particles of greater and greaterfineness.

In the form of construction shown inFig. 4 the filteringis also effectedin two stages but by means of two filter cartridges disposed in'axialalignment, on opposite sides of the cartridge supporting partition 5.The tubular body '10 mounted in the inlet compartment is identical tothat shown in Fig. 1 that is to say that the cones 3 perforated at theirapices project towards the interior and the filter sleeve 20 isstretched about the exterior circumference so .as to be applied againstthe body by the "pressure of the liquid to be filtered. The fixation ofthe core'lc is as shown in Fig. l. The tubular core 1d mounted in theoutlet compartment of the filter apparatus differs from core in that theembossed cones 3d project towards the exterior and the filter sleeve 2dis disposed against the internal circumference so as to be appliedagainst the latter by the pressure of the liquid flowingin this casefrom the interior to the exterior. Otherwise the construction andoperation are similar.

Figs. 5. 6,7, 8 and 9 show by way of example a filter apparatusconstructed for using cartridges of the type shown in Fig. 1. Thisfilter apparatus comprises a casing 13 provided on two opposite sideswith two tubular fittings '14 and 15 flanged for connection to pipes.One lateral side of this casing is provided with a removable cover 16.This cover has an internal transverse rib 17 perpendicular to the axesof the tubular fittings 14, 15 which rib is connected to another rib 18as a continuation thereof. Rib 18 is integral with the other three sidewalls of "the casing .13. The casing thus has in its interior a sort offrame with a rectangular opening in which is nested a cartridgesupporting cup 19. One side of'this frame is removable with cover 16.For mounting the cup-like member 19, it is provided with a peripheralflange 20 in which is formed a continuous groove 21 (Fig. 8), and theribs 17, 18 are so dimensioned that they can engage the groove. Henceafter removal of the plate 16 it is possible to withdraw from the sideof the casing thus opened, the cartridge supporting cup-like member bysliding it in the two opposite lateral grooves (not shown in thedrawing). To replace the said plate the procedure is reversed.

The ribs 17, 18 form along with the cup-like member apartition dividingthe interior of the easing into two compartments 22. and 23. The liquidto be filtered is assumed to enter into the compartment 22 and todischarge from the compartment 23.

Since there exists a certain diiference in pressure in the compartments22, 23 it is necessary to provide a seal between the ribs 17, 18 and thegroove 21. This consists of a flexible annular tube 24 having anexternal diameter equal to or slightly greater than the width ofthe-grove '21. This tube contains a ring 25 formed of a helicalspringcapable'of giving it a certain firmness and of pressing it into thebottom of the groove. After it'is put in place this tube substantiallyfills the groove leaving room enough only for the entry of the rib 17 or18. The pressure of the fluid being higher in the compartment 22 than inthe compartment 23 the fluid has a tendency to flow from compartment 22into compartment 23 directly between the rib and the groove in case ofimperfect sealing or absence of a sealing gasket. According to .theinvention the fluid penetrating into the groove :acts on the flexibletube and tends to crush or collapse .it, thus compressing the aircontained therein so .thabthe tubeisstrongly appliedagainst the bottomof .the.groove, against-its sides on-the outlet compartment side andagainst the rib. Sealing is thus perfectly guaranteed.

0n the bottom of the cup-like partition and within the inlet compartment22 are mounted several cartridges of the kind shown in Fig. 1.

Figs. 10-13 show how :a ,simple filter cartridge may be formed by usinga tubular body of embossed sheet metal but in replacing the sleeve offilter cloth'by a filter material formed by a pile of discs havingmicrogrooves on both faces thereof.

Fig. 13 shows the principle of this filter material. It shows on a verylarge scale two planediscs of suitable material in superposed position.On the upper face of the lower disc 26 are traced from one edge to theother parallel grooves 26:: of a depth which is micrometric or of theorder of one hundredth of a millimeter. On the lower face of the upperdisc .27 are tracedfrom edge toedge parallel grooves 27a also of a depthwhichzis micrometric or of the order of one hundredth of amillimeter.Thegrooves of the two discs extendtransversely to each other so thatthose of the lower disc cross those of the upper disc. Thus the groovesform channels of a certain cross-section allowing passage of liquid .butretaining particles coarser than this cross-section.

Based on this principle a filter cartridge is composed of discs whichmay be annular but are preferably vin the form of square frames as shown'in'Fig. 12. It is necessary to hold the discs ina determinedorientation such that the grooves in the contacting faces of twoconsecutive discs cross each other as described. For annular discs it isnecessary to provide them with a notch adapted to engage a guide or toprovide similar means. In any case it is essential to; provide twogroups of discs, for example having notches displaced by a certain anglerelative to the direction ,of the grooves.

The use of discs in the form of square frames simplifies productionsince all the discs may be identical. It is necessary that the discs bestacked waroundatubular body of square section as shown .in Fig. 11 withconsecutive discs alternately disposed so that their grooves cross eachother in the manner clearly shown in ,Fig. .12. For-simplicity the discsshownin this figure have grooves on one face only although actually theyhave similar grooves on both faces extending in the same direction. Theform of construction of the cartridge with stacked discs as shown inFig. '10 is only intended to 'be .anexample. In this case a cartridgesupporting partition '28 having on the face directed towards theinlet-compartment a square boss 29 exactly fitting the core 30 of squaresection. In the center of the boss is threadedly secured a rod 31extending into therinterior of the inlet compartment and screwthreadedat its free end. "The discs 32 with microgrooves 32a in their surfacesare stacked on the core in the mannerhereinbefore described. The lower'disc rests on a sealing gasket 33. Another sealing gasket 34 is appliedon the upper disc.

The clamping of the stack of discs is effected by a cover 35 similar tocover 9, -but in which the gutter'or peripheral recess 36 is providedwith an outwardly .extending flange 37 which'bears on the sealinggasket34. The cover 35 is in turn clamped in place by a nut 38 withexpansion compensating means 39. The peripheral gutter 36 is disposed insuch manner that it provides play at the upper end of the core duringthe compression of the discs.

Without departing from the scope of the invention the cartridges coremay be made of material otherthan rnetal, especially a plastic material.Other mounting devices and other cartridges may be used While remainingwithin the scope of the invention.

Having described my invention, I claim:

1. A filtering device comprisinga filter cartridge composedof a rigidtubular bo'dyof sheet material' having small perforated conical elementsprojecting -from onesurface thereof, the "opposite surtace being smooth,a

filter sleeve covering the smooth surface of the body and having itsends turned over the end edges of the tubular body, a supporting platefor the cartridge and having a groove for receiving one end of thecartridge, an annular fluid sealing collar of U-shaped cross-sectionmounted on the one end of the cartridge and positioned in said groove, arod fixedly mounted on said plate and positioned axially of thecartridge, a cover cap over the opposite end of the cartridge, andclamping means engaging the rod for holding the cartridge and cover capin assembled relation with the plate.

2. A filtering device as set forth in claim 1, wherein a second filtercartridge composed of a tubular body, a sleeve of filter material, cap,rod, and clamping means are mounted on the opposite side of thesupporting plate in axial alignment with the first-mentioned rod andcartridge, and wherein one filter sleeve is mounted over the exteriorsurface of one tubular body located on one side of the plate, and thesecond filter sleeve is mounted over the 6 l interior surface of theother tubular body located on the other side of the plate.

References Cited in the file of this patent UNITED STATES PATENTS756,519 Kneuper Aug. 8, 1905 802,714 Smith Oct. 24, 1905 1,093,684Campbell Apr. 21, 1914 1,224,213 Rosenthal May 1, 1917 1,288,508 ChapinDec. 24, 1918 1,540,325 Fuller June 2, 1925 2,265,550 Smith Dec. 9, 19412,271,054 Williams Jan. 27, 1942 2,584,387 Harvuot Feb. 5, 19522,711,253 Mills June 21, 1955 2,813,632 Muller Nov. 19, 1957 FOREIGNPATENTS 15,491 Great Britain May 28, 1908 1,108,096 France Aug. 17, 1955

